Originally Posted by
mahasamatman
A good travel agent (i.e., the only kind you should ever use) should be able to put multiple tickets on one PNR. But they cannot be combined after the fact - you have to purchase it that way.
The OP should be able to build the same with a third-party site -- Expedia, Orbitz, whatever. Or even use UA reservations to build the whole thing on one ticket.
Problem is sometimes low fares don't allow combining with other airlines' fares. I see this a lot in Europe, and at times domestically.